During the Second World War Royal Navy ratings wore two different badges on their jumpers. One was a badge of rate, indicating their rank, and the other was a specialism badge that showed what trade the sailor belonged to and his ability within that trade. The two different badges were, to a degree, unrelated and the qualification in one was not necessarily an indication that the man had also progressed in the other. The range of trade badges had not yet reached the numbers it would in the post war period, but there were still a number of different trades and accompanying badges being used and one of the most common consisted of a pair of crossed guns, here in red embroidery:
The crossed guns indicate the Gunnery branch, however the lack of any star, crown or letter shows that this is for a gunner who has not yet completed his training so is not yet qualified. The badge has been machine embroidered onto a piece of felt which has a piece of white cotton backing for strength:
Douglas Rubery was a Royal Navy Gunner in the Second World War:
Along with four other English sailors I was to look after the gunnery on this merchant ship. I was put on DEMs (ie defensively equipped merchant ships). The crew of the merchant ship consisted of Norwegian personnel, except for the radio operator who was Estonian. We were to travel back and forth over the Atlantic bringing supplies from America back to England. The Norwegian crew consisted of hardened sailors and we found it very difficult to adjust to their predilection for raw fish. After a few weeks of this we could endure no more and managed to get provisions on board for a near English diet. It is amazing that I still can eat fish albeit cooked, but I have to say that it is one of my favourite dishes.
We were never informed of the cargo we were to pick up and escort back to England. We were there to look after the gunnery ie stripping the guns down and keeping them in good order. Of course our other main job was to keep watch and make sure those infamous u boats didn’t target us.
Tales from the Supply Depot 
The first high points in a serviceman’s career were the awarding of a cap badge after a few week’s service, the infamous ‘cornflake’ that meant you had learned enough to be able to salute properly.
Then after initial trades training, the awarding of the branch cap badge you’d wear for the rest of your career, assuming you didn’t remuster to a different branch later on like I did 😉
started with this
spent the most time with this
Your trade qualification badge
Then the Command badge on your first posting to an operational Unit
Once you had all of those, then you were a ‘real’ serviceman/woman, not before 😉
Granted, we didn’t get trade specific badges until after I’d been in for quite awhile and they eventually took the air command badge away for airforce personnel figuring the blue uniform was enough, although those wearing Navy or Army uniforms still wore them if serving on Airforce Units o.O